This invention relates generally to an exhaust liner for a turbine engine. More particularly, this invention relates to an exhaust liner with impingement cooling of an end portion of the exhaust liner.
A gas turbine engine includes a compressor, a combustor and a turbine. Compressed air mixed with fuel in the combustor generates an axial flow of hot gases. The hot gases flow through the turbine and against a plurality of turbine blades. The turbine blades transform the flow of hot gases into mechanical energy for driving a rotor shaft that in turn drives the compressor. An exhaust liner assembly directs, contains, and protects other engine components from hot combustion gases exhausted from the turbine engine.
The exhaust liner assembly typically includes a hot side liner and a cold side liner spaced radially apart. The hot side liner includes a surface in contact with the hot combustion gases. The cold side liner includes a plurality of openings for cooling air. The hot side liner is cooled to maintain a desired temperature and to protect against exposure to the hot combustion gases. Cooling is provided by cooling air flowing through the cold side liner and impinging on the hot side liner. The impingement flow provides the desired cooling effects by directly striking the hot side liner.
Although the impingement flow is typically adequate for cooling the hot side liner and maintaining a desired temperature, there are some locations, such as end regions where support structures may cover a portion of the cold side liner preventing cooling holes from communicating with a source of cooling air flow. In such locations, cooling is typically accomplished by allowing cooling flow to migrate within the space between the cold side liner and the hot side liner. Disadvantageously, the inability to impinge cooling flow against the hot side liner reduces cooling efficiency.
Accordingly, it is desirable to develop an exhaust liner with improved features for providing impingement cooling of a hot side liner in local regions blocked from direct communication with cooling air flow.